drivers/target/target_core_rd.c

   1 /*******************************************************************************
   2  * Filename:  target_core_rd.c
   3  *
   4  * This file contains the Storage Engine <-> Ramdisk transport
   5  * specific functions.
   6  *
   7  * (c) Copyright 2003-2013 Datera, Inc.
   8  *
   9  * Nicholas A. Bellinger <nab@kernel.org>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  24  *
  25  ******************************************************************************/
  26
  27 #include <linux/string.h>
  28 #include <linux/parser.h>
  29 #include <linux/highmem.h>
  30 #include <linux/timer.h>
  31 #include <linux/scatterlist.h>
  32 #include <linux/slab.h>
  33 #include <linux/spinlock.h>
  34 #include <scsi/scsi_proto.h>
  35
  36 #include <target/target_core_base.h>
  37 #include <target/target_core_backend.h>
  38
  39 #include "target_core_rd.h"
  40
  41 static inline struct rd_dev *RD_DEV(struct se_device *dev)
  42 {
  43         return container_of(dev, struct rd_dev, dev);
  44 }
  45
  46 static int rd_attach_hba(struct se_hba *hba, u32 host_id)
  47 {
  48         struct rd_host *rd_host;
  49
  50         rd_host = kzalloc(sizeof(*rd_host), GFP_KERNEL);
  51         if (!rd_host)
  52                 return -ENOMEM;
  53
  54         rd_host->rd_host_id = host_id;
  55
  56         hba->hba_ptr = rd_host;
  57
  58         pr_debug("CORE_HBA[%d] - TCM Ramdisk HBA Driver %s on"
  59                 " Generic Target Core Stack %s\n", hba->hba_id,
  60                 RD_HBA_VERSION, TARGET_CORE_VERSION);
  61
  62         return 0;
  63 }
  64
  65 static void rd_detach_hba(struct se_hba *hba)
  66 {
  67         struct rd_host *rd_host = hba->hba_ptr;
  68
  69         pr_debug("CORE_HBA[%d] - Detached Ramdisk HBA: %u from"
  70                 " Generic Target Core\n", hba->hba_id, rd_host->rd_host_id);
  71
  72         kfree(rd_host);
  73         hba->hba_ptr = NULL;
  74 }
  75
  76 static u32 rd_release_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table,
  77                                  u32 sg_table_count)
  78 {
  79         struct page *pg;
  80         struct scatterlist *sg;
  81         u32 i, j, page_count = 0, sg_per_table;
  82
  83         for (i = 0; i < sg_table_count; i++) {
  84                 sg = sg_table[i].sg_table;
  85                 sg_per_table = sg_table[i].rd_sg_count;
  86
  87                 for (j = 0; j < sg_per_table; j++) {
  88                         pg = sg_page(&sg[j]);
  89                         if (pg) {
  90                                 __free_page(pg);
  91                                 page_count++;
  92                         }
  93                 }
  94                 kfree(sg);
  95         }
  96
  97         kfree(sg_table);
  98         return page_count;
  99 }
 100
 101 static void rd_release_device_space(struct rd_dev *rd_dev)
 102 {
 103         u32 page_count;
 104
 105         if (!rd_dev->sg_table_array || !rd_dev->sg_table_count)
 106                 return;
 107
 108         page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_table_array,
 109                                           rd_dev->sg_table_count);
 110
 111         pr_debug("CORE_RD[%u] - Released device space for Ramdisk"
 112                 " Device ID: %u, pages %u in %u tables total bytes %lu\n",
 113                 rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
 114                 rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
 115
 116         rd_dev->sg_table_array = NULL;
 117         rd_dev->sg_table_count = 0;
 118 }
 119
 120
 121 /*      rd_build_device_space():
 122  *
 123  *
 124  */
 125 static int rd_allocate_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table,
 126                                  u32 total_sg_needed, unsigned char init_payload)
 127 {
 128         u32 i = 0, j, page_offset = 0, sg_per_table;
 129         u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 130                                 sizeof(struct scatterlist));
 131         struct page *pg;
 132         struct scatterlist *sg;
 133         unsigned char *p;
 134
 135         while (total_sg_needed) {
 136                 unsigned int chain_entry = 0;
 137
 138                 sg_per_table = (total_sg_needed > max_sg_per_table) ?
 139                         max_sg_per_table : total_sg_needed;
 140
 141                 /*
 142                  * Reserve extra element for chain entry
 143                  */
 144                 if (sg_per_table < total_sg_needed)
 145                         chain_entry = 1;
 146
 147                 sg = kcalloc(sg_per_table + chain_entry, sizeof(*sg),
 148                                 GFP_KERNEL);
 149                 if (!sg)
 150                         return -ENOMEM;
 151
 152                 sg_init_table(sg, sg_per_table + chain_entry);
 153
 154                 if (i > 0) {
 155                         sg_chain(sg_table[i - 1].sg_table,
 156                                  max_sg_per_table + 1, sg);
 157                 }
 158
 159                 sg_table[i].sg_table = sg;
 160                 sg_table[i].rd_sg_count = sg_per_table;
 161                 sg_table[i].page_start_offset = page_offset;
 162                 sg_table[i++].page_end_offset = (page_offset + sg_per_table)
 163                                                 - 1;
 164
 165                 for (j = 0; j < sg_per_table; j++) {
 166                         pg = alloc_pages(GFP_KERNEL, 0);
 167                         if (!pg) {
 168                                 pr_err("Unable to allocate scatterlist"
 169                                         " pages for struct rd_dev_sg_table\n");
 170                                 return -ENOMEM;
 171                         }
 172                         sg_assign_page(&sg[j], pg);
 173                         sg[j].length = PAGE_SIZE;
 174
 175                         p = kmap(pg);
 176                         memset(p, init_payload, PAGE_SIZE);
 177                         kunmap(pg);
 178                 }
 179
 180                 page_offset += sg_per_table;
 181                 total_sg_needed -= sg_per_table;
 182         }
 183
 184         return 0;
 185 }
 186
 187 static int rd_build_device_space(struct rd_dev *rd_dev)
 188 {
 189         struct rd_dev_sg_table *sg_table;
 190         u32 sg_tables, total_sg_needed;
 191         u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 192                                 sizeof(struct scatterlist));
 193         int rc;
 194
 195         if (rd_dev->rd_page_count <= 0) {
 196                 pr_err("Illegal page count: %u for Ramdisk device\n",
 197                        rd_dev->rd_page_count);
 198                 return -EINVAL;
 199         }
 200
 201         /* Don't need backing pages for NULLIO */
 202         if (rd_dev->rd_flags & RDF_NULLIO)
 203                 return 0;
 204
 205         total_sg_needed = rd_dev->rd_page_count;
 206
 207         sg_tables = (total_sg_needed / max_sg_per_table) + 1;
 208         sg_table = kcalloc(sg_tables, sizeof(*sg_table), GFP_KERNEL);
 209         if (!sg_table)
 210                 return -ENOMEM;
 211
 212         rd_dev->sg_table_array = sg_table;
 213         rd_dev->sg_table_count = sg_tables;
 214
 215         rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0x00);
 216         if (rc)
 217                 return rc;
 218
 219         pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
 220                  " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
 221                  rd_dev->rd_dev_id, rd_dev->rd_page_count,
 222                  rd_dev->sg_table_count);
 223
 224         return 0;
 225 }
 226
 227 static void rd_release_prot_space(struct rd_dev *rd_dev)
 228 {
 229         u32 page_count;
 230
 231         if (!rd_dev->sg_prot_array || !rd_dev->sg_prot_count)
 232                 return;
 233
 234         page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_prot_array,
 235                                           rd_dev->sg_prot_count);
 236
 237         pr_debug("CORE_RD[%u] - Released protection space for Ramdisk"
 238                  " Device ID: %u, pages %u in %u tables total bytes %lu\n",
 239                  rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
 240                  rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
 241
 242         rd_dev->sg_prot_array = NULL;
 243         rd_dev->sg_prot_count = 0;
 244 }
 245
 246 static int rd_build_prot_space(struct rd_dev *rd_dev, int prot_length, int block_size)
 247 {
 248         struct rd_dev_sg_table *sg_table;
 249         u32 total_sg_needed, sg_tables;
 250         u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 251                                 sizeof(struct scatterlist));
 252         int rc;
 253
 254         if (rd_dev->rd_flags & RDF_NULLIO)
 255                 return 0;
 256         /*
 257          * prot_length=8byte dif data
 258          * tot sg needed = rd_page_count * (PGSZ/block_size) *
 259          *                 (prot_length/block_size) + pad
 260          * PGSZ canceled each other.
 261          */
 262         total_sg_needed = (rd_dev->rd_page_count * prot_length / block_size) + 1;
 263
 264         sg_tables = (total_sg_needed / max_sg_per_table) + 1;
 265         sg_table = kcalloc(sg_tables, sizeof(*sg_table), GFP_KERNEL);
 266         if (!sg_table)
 267                 return -ENOMEM;
 268
 269         rd_dev->sg_prot_array = sg_table;
 270         rd_dev->sg_prot_count = sg_tables;
 271
 272         rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0xff);
 273         if (rc)
 274                 return rc;
 275
 276         pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u prot space of"
 277                  " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
 278                  rd_dev->rd_dev_id, total_sg_needed, rd_dev->sg_prot_count);
 279
 280         return 0;
 281 }
 282
 283 static struct se_device *rd_alloc_device(struct se_hba *hba, const char *name)
 284 {
 285         struct rd_dev *rd_dev;
 286         struct rd_host *rd_host = hba->hba_ptr;
 287
 288         rd_dev = kzalloc(sizeof(*rd_dev), GFP_KERNEL);
 289         if (!rd_dev)
 290                 return NULL;
 291
 292         rd_dev->rd_host = rd_host;
 293
 294         return &rd_dev->dev;
 295 }
 296
 297 static int rd_configure_device(struct se_device *dev)
 298 {
 299         struct rd_dev *rd_dev = RD_DEV(dev);
 300         struct rd_host *rd_host = dev->se_hba->hba_ptr;
 301         int ret;
 302
 303         if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) {
 304                 pr_debug("Missing rd_pages= parameter\n");
 305                 return -EINVAL;
 306         }
 307
 308         ret = rd_build_device_space(rd_dev);
 309         if (ret < 0)
 310                 goto fail;
 311
 312         dev->dev_attrib.hw_block_size = RD_BLOCKSIZE;
 313         dev->dev_attrib.hw_max_sectors = UINT_MAX;
 314         dev->dev_attrib.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH;
 315         dev->dev_attrib.is_nonrot = 1;
 316
 317         rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;
 318
 319         pr_debug("CORE_RD[%u] - Added TCM MEMCPY Ramdisk Device ID: %u of"
 320                 " %u pages in %u tables, %lu total bytes\n",
 321                 rd_host->rd_host_id, rd_dev->rd_dev_id, rd_dev->rd_page_count,
 322                 rd_dev->sg_table_count,
 323                 (unsigned long)(rd_dev->rd_page_count * PAGE_SIZE));
 324
 325         return 0;
 326
 327 fail:
 328         rd_release_device_space(rd_dev);
 329         return ret;
 330 }
 331
 332 static void rd_dev_call_rcu(struct rcu_head *p)
 333 {
 334         struct se_device *dev = container_of(p, struct se_device, rcu_head);
 335         struct rd_dev *rd_dev = RD_DEV(dev);
 336
 337         kfree(rd_dev);
 338 }
 339
 340 static void rd_free_device(struct se_device *dev)
 341 {
 342         struct rd_dev *rd_dev = RD_DEV(dev);
 343
 344         rd_release_device_space(rd_dev);
 345         call_rcu(&dev->rcu_head, rd_dev_call_rcu);
 346 }
 347
 348 static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page)
 349 {
 350         struct rd_dev_sg_table *sg_table;
 351         u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 352                                 sizeof(struct scatterlist));
 353
 354         i = page / sg_per_table;
 355         if (i < rd_dev->sg_table_count) {
 356                 sg_table = &rd_dev->sg_table_array[i];
 357                 if ((sg_table->page_start_offset <= page) &&
 358                     (sg_table->page_end_offset >= page))
 359                         return sg_table;
 360         }
 361
 362         pr_err("Unable to locate struct rd_dev_sg_table for page: %u\n",
 363                         page);
 364
 365         return NULL;
 366 }
 367
 368 static struct rd_dev_sg_table *rd_get_prot_table(struct rd_dev *rd_dev, u32 page)
 369 {
 370         struct rd_dev_sg_table *sg_table;
 371         u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 372                                 sizeof(struct scatterlist));
 373
 374         i = page / sg_per_table;
 375         if (i < rd_dev->sg_prot_count) {
 376                 sg_table = &rd_dev->sg_prot_array[i];
 377                 if ((sg_table->page_start_offset <= page) &&
 378                      (sg_table->page_end_offset >= page))
 379                         return sg_table;
 380         }
 381
 382         pr_err("Unable to locate struct prot rd_dev_sg_table for page: %u\n",
 383                         page);
 384
 385         return NULL;
 386 }
 387
 388 static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, bool is_read)
 389 {
 390         struct se_device *se_dev = cmd->se_dev;
 391         struct rd_dev *dev = RD_DEV(se_dev);
 392         struct rd_dev_sg_table *prot_table;
 393         struct scatterlist *prot_sg;
 394         u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size;
 395         u32 prot_offset, prot_page;
 396         u32 prot_npages __maybe_unused;
 397         u64 tmp;
 398         sense_reason_t rc = 0;
 399
 400         tmp = cmd->t_task_lba * se_dev->prot_length;
 401         prot_offset = do_div(tmp, PAGE_SIZE);
 402         prot_page = tmp;
 403
 404         prot_table = rd_get_prot_table(dev, prot_page);
 405         if (!prot_table)
 406                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 407
 408         prot_sg = &prot_table->sg_table[prot_page -
 409                                         prot_table->page_start_offset];
 410
 411         if (se_dev->dev_attrib.pi_prot_verify) {
 412                 if (is_read)
 413                         rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors, 0,
 414                                             prot_sg, prot_offset);
 415                 else
 416                         rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors, 0,
 417                                             cmd->t_prot_sg, 0);
 418         }
 419         if (!rc)
 420                 sbc_dif_copy_prot(cmd, sectors, is_read, prot_sg, prot_offset);
 421
 422         return rc;
 423 }
 424
 425 static sense_reason_t
 426 rd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 427               enum dma_data_direction data_direction)
 428 {
 429         struct se_device *se_dev = cmd->se_dev;
 430         struct rd_dev *dev = RD_DEV(se_dev);
 431         struct rd_dev_sg_table *table;
 432         struct scatterlist *rd_sg;
 433         struct sg_mapping_iter m;
 434         u32 rd_offset;
 435         u32 rd_size;
 436         u32 rd_page;
 437         u32 src_len;
 438         u64 tmp;
 439         sense_reason_t rc;
 440
 441         if (dev->rd_flags & RDF_NULLIO) {
 442                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 443                 return 0;
 444         }
 445
 446         tmp = cmd->t_task_lba * se_dev->dev_attrib.block_size;
 447         rd_offset = do_div(tmp, PAGE_SIZE);
 448         rd_page = tmp;
 449         rd_size = cmd->data_length;
 450
 451         table = rd_get_sg_table(dev, rd_page);
 452         if (!table)
 453                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 454
 455         rd_sg = &table->sg_table[rd_page - table->page_start_offset];
 456
 457         pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n",
 458                         dev->rd_dev_id,
 459                         data_direction == DMA_FROM_DEVICE ? "Read" : "Write",
 460                         cmd->t_task_lba, rd_size, rd_page, rd_offset);
 461
 462         if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
 463             data_direction == DMA_TO_DEVICE) {
 464                 rc = rd_do_prot_rw(cmd, false);
 465                 if (rc)
 466                         return rc;
 467         }
 468
 469         src_len = PAGE_SIZE - rd_offset;
 470         sg_miter_start(&m, sgl, sgl_nents,
 471                         data_direction == DMA_FROM_DEVICE ?
 472                                 SG_MITER_TO_SG : SG_MITER_FROM_SG);
 473         while (rd_size) {
 474                 u32 len;
 475                 void *rd_addr;
 476
 477                 sg_miter_next(&m);
 478                 if (!(u32)m.length) {
 479                         pr_debug("RD[%u]: invalid sgl %p len %zu\n",
 480                                  dev->rd_dev_id, m.addr, m.length);
 481                         sg_miter_stop(&m);
 482                         return TCM_INCORRECT_AMOUNT_OF_DATA;
 483                 }
 484                 len = min((u32)m.length, src_len);
 485                 if (len > rd_size) {
 486                         pr_debug("RD[%u]: size underrun page %d offset %d "
 487                                  "size %d\n", dev->rd_dev_id,
 488                                  rd_page, rd_offset, rd_size);
 489                         len = rd_size;
 490                 }
 491                 m.consumed = len;
 492
 493                 rd_addr = sg_virt(rd_sg) + rd_offset;
 494
 495                 if (data_direction == DMA_FROM_DEVICE)
 496                         memcpy(m.addr, rd_addr, len);
 497                 else
 498                         memcpy(rd_addr, m.addr, len);
 499
 500                 rd_size -= len;
 501                 if (!rd_size)
 502                         continue;
 503
 504                 src_len -= len;
 505                 if (src_len) {
 506                         rd_offset += len;
 507                         continue;
 508                 }
 509
 510                 /* rd page completed, next one please */
 511                 rd_page++;
 512                 rd_offset = 0;
 513                 src_len = PAGE_SIZE;
 514                 if (rd_page <= table->page_end_offset) {
 515                         rd_sg++;
 516                         continue;
 517                 }
 518
 519                 table = rd_get_sg_table(dev, rd_page);
 520                 if (!table) {
 521                         sg_miter_stop(&m);
 522                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 523                 }
 524
 525                 /* since we increment, the first sg entry is correct */
 526                 rd_sg = table->sg_table;
 527         }
 528         sg_miter_stop(&m);
 529
 530         if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
 531             data_direction == DMA_FROM_DEVICE) {
 532                 rc = rd_do_prot_rw(cmd, true);
 533                 if (rc)
 534                         return rc;
 535         }
 536
 537         target_complete_cmd(cmd, SAM_STAT_GOOD);
 538         return 0;
 539 }
 540
 541 enum {
 542         Opt_rd_pages, Opt_rd_nullio, Opt_err
 543 };
 544
 545 static match_table_t tokens = {
 546         {Opt_rd_pages, "rd_pages=%d"},
 547         {Opt_rd_nullio, "rd_nullio=%d"},
 548         {Opt_err, NULL}
 549 };
 550
 551 static ssize_t rd_set_configfs_dev_params(struct se_device *dev,
 552                 const char *page, ssize_t count)
 553 {
 554         struct rd_dev *rd_dev = RD_DEV(dev);
 555         char *orig, *ptr, *opts;
 556         substring_t args[MAX_OPT_ARGS];
 557         int ret = 0, arg, token;
 558
 559         opts = kstrdup(page, GFP_KERNEL);
 560         if (!opts)
 561                 return -ENOMEM;
 562
 563         orig = opts;
 564
 565         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 566                 if (!*ptr)
 567                         continue;
 568
 569                 token = match_token(ptr, tokens, args);
 570                 switch (token) {
 571                 case Opt_rd_pages:
 572                         match_int(args, &arg);
 573                         rd_dev->rd_page_count = arg;
 574                         pr_debug("RAMDISK: Referencing Page"
 575                                 " Count: %u\n", rd_dev->rd_page_count);
 576                         rd_dev->rd_flags |= RDF_HAS_PAGE_COUNT;
 577                         break;
 578                 case Opt_rd_nullio:
 579                         match_int(args, &arg);
 580                         if (arg != 1)
 581                                 break;
 582
 583                         pr_debug("RAMDISK: Setting NULLIO flag: %d\n", arg);
 584                         rd_dev->rd_flags |= RDF_NULLIO;
 585                         break;
 586                 default:
 587                         break;
 588                 }
 589         }
 590
 591         kfree(orig);
 592         return (!ret) ? count : ret;
 593 }
 594
 595 static ssize_t rd_show_configfs_dev_params(struct se_device *dev, char *b)
 596 {
 597         struct rd_dev *rd_dev = RD_DEV(dev);
 598
 599         ssize_t bl = sprintf(b, "TCM RamDisk ID: %u  RamDisk Makeup: rd_mcp\n",
 600                         rd_dev->rd_dev_id);
 601         bl += sprintf(b + bl, "        PAGES/PAGE_SIZE: %u*%lu"
 602                         "  SG_table_count: %u  nullio: %d\n", rd_dev->rd_page_count,
 603                         PAGE_SIZE, rd_dev->sg_table_count,
 604                         !!(rd_dev->rd_flags & RDF_NULLIO));
 605         return bl;
 606 }
 607
 608 static sector_t rd_get_blocks(struct se_device *dev)
 609 {
 610         struct rd_dev *rd_dev = RD_DEV(dev);
 611
 612         unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
 613                         dev->dev_attrib.block_size) - 1;
 614
 615         return blocks_long;
 616 }
 617
 618 static int rd_init_prot(struct se_device *dev)
 619 {
 620         struct rd_dev *rd_dev = RD_DEV(dev);
 621
 622         if (!dev->dev_attrib.pi_prot_type)
 623                 return 0;
 624
 625         return rd_build_prot_space(rd_dev, dev->prot_length,
 626                                    dev->dev_attrib.block_size);
 627 }
 628
 629 static void rd_free_prot(struct se_device *dev)
 630 {
 631         struct rd_dev *rd_dev = RD_DEV(dev);
 632
 633         rd_release_prot_space(rd_dev);
 634 }
 635
 636 static struct sbc_ops rd_sbc_ops = {
 637         .execute_rw             = rd_execute_rw,
 638 };
 639
 640 static sense_reason_t
 641 rd_parse_cdb(struct se_cmd *cmd)
 642 {
 643         return sbc_parse_cdb(cmd, &rd_sbc_ops);
 644 }
 645
 646 static const struct target_backend_ops rd_mcp_ops = {
 647         .name                   = "rd_mcp",
 648         .inquiry_prod           = "RAMDISK-MCP",
 649         .inquiry_rev            = RD_MCP_VERSION,
 650         .attach_hba             = rd_attach_hba,
 651         .detach_hba             = rd_detach_hba,
 652         .alloc_device           = rd_alloc_device,
 653         .configure_device       = rd_configure_device,
 654         .free_device            = rd_free_device,
 655         .parse_cdb              = rd_parse_cdb,
 656         .set_configfs_dev_params = rd_set_configfs_dev_params,
 657         .show_configfs_dev_params = rd_show_configfs_dev_params,
 658         .get_device_type        = sbc_get_device_type,
 659         .get_blocks             = rd_get_blocks,
 660         .init_prot              = rd_init_prot,
 661         .free_prot              = rd_free_prot,
 662         .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 663 };
 664
 665 int __init rd_module_init(void)
 666 {
 667         return transport_backend_register(&rd_mcp_ops);
 668 }
 669
 670 void rd_module_exit(void)
 671 {
 672         target_backend_unregister(&rd_mcp_ops);
 673 }